What Is a Slide Ruler?

Mathematicians and scientists are notorious for the tools they implement to make their lives and jobs easier. One of the more arcane tools is the slide ruler, which has been replaced for some by more complex instruments, but is still used by students, accountants, and various other professionals.

Purpose

Slide rulers are used as a reference tool that gives the answers to a variety of math problems, including multiplication and division.

Identification

Slide rulers are rectangular and long, like traditional rulers, or they are circular. They all have a plastic slide that can be moved across the ruler body.

How Does It Function?

In order to use a slide ruler, you have to slide the plastic piece to the numbers you are looking to include in the equation; a single line matches these numbers to their corresponding answers.

Types

There are numerous types of slide rulers that focus on various problems. The base problems are multiplication and division, though specialized rulers are made for accounting or engineering problems as well.

Benefits

Slide rules offer a number of benefits: they are easy to use and make; they do not need a power source, which makes them highly portable; and they can offer the answer to difficult equations with merely a glance.

Resources

• Slide Ruler History & Terms